Use quaternary pyridinium salts as vasoprotective agents

ABSTRACT

The invention relates to the use of quaternary pyridinium salts of formula (I), 
                         
wherein R is NH 2 , CH 3 , or N(H)CH 2 OH group, and X is pharmaceutically acceptable counterion, for the preparation of vasoprotective agent for the treatment or prevention of conditions or diseases associated with dysfunction of vascular endothelium, oxidative stress, and/or insufficient production of endothelial prostacyclin PGI 2 , in particular but not exclusively if the above coincides with hypercholesterolemia, hypertriglyceridemia or low HDL level.

The present invention relates to the use of certain quaternary pyridinium salts for the preparation of a vasoprotective agent for the treatment and/or prevention of conditions or diseases associated with dysfunction of vascular endothelium, oxidative stress, and/or insufficient production of endothelial prostacyclin (PGI₂), in particular but not exclusively if the above coincides with hypercholesterolemia/hypertriglyceridemia, as well as the use of pyridinium salts for oral use in diet supplementation.

There is increasing evidence that endothelial dysfunction plays a key role in the formation and progression of atherosclerotic plaque. Endothelial dysfunction has recently gained diagnostic, prognostic and therapeutic significance in atherothrombosis (Heitzer T, Schlinzig T, Krohn K, Meinertz T, Munzel T. Endothelial dysfunction, oxidative stress, and risk of cardiovascular events in patients with coronary artery disease. Circulation 2001; 104:2673-2678; Schachinger V, Britten M B, Zeiher A M. Prognostic impact of coronary vasodilator dysfunction on adverse long-term outcome of coronary heart disease. Circulation 2000; 101:1899-1906; Perticone F, Ceravolo R, Pujia A, Ventura G, Iacopino S, Scozzafava A, Ferraro A, Chello M, Mastroroberto P, Verdecchia P, Schillaci G. Prognostic significance of endothelial dysfunction in hypertensive patients. Circulation 2001; 104:191-196; Suwaidi J A, Hamasaki S, Higano S T, Nishimura R A, Holmes D R, Jr., Lerman A. Long-term follow-up of patients with mild coronary artery disease and endothelial dysfunction. Circulation 2000; 101:948-954). Clinically, endothelial dysfunction is identified as impairement of biological activity of NO, which is diagnosed as an impairment of vasodilating NO activity. Impairment of NO activity coincides with oxidant stress (Heitzer T, Schlinzig T, Krohn K, Meinertz T, Munzel T. Endothelial dysfunction, oxidative stress, and risk of cardiovascular events in patients with coronary artery disease. Circulation 2001; 104:2673-2678) and impairment of PGI₂ synthesis (Kyrle P A, Minar E, Brenner B, Eichler H G, Heistinger M, Marosi L, Lechner K. Thromboxane A₂ and prostacyclin generation in the microvasculature of patients with atherosclerosis—effect of low-dose aspirin. Thromb Haemost 1989; 61:374-377), although systemic level of PGI₂ may be elevated. Indeed, several years ago it was proposed that increased lipid peroxidation might promote development of atherosclerosis owing to selective impairment of prostacyclin synthesis in endothelial cells and subsequent activation of platelets (Gryglewski R J. Prostacyclin and atherosclerosis. TIPS 1980; 1:164-168; Gryglewski R J. Prostaglandins, platelets, and atherosclerosis. CRC Crit. Rev Biochem 1980; 7:291-338; Gryglewski R J, Szczeklik A. Prostacyclin and atherosclerosis−experimental and clinical approach. 1983; 213-226). This concept was then supported experimentally. It is apparent now that impairment of PGI₂ synthesis in endothelium may lead to the excessive stimulation of TP receptors in endothelium and vascular smooth muscle cells by TXA₂, PGH₂ or other eicosanoids, and to subsequent vasoconstriction, platelet aggregation, and inflammatory response of endothelium as well as endothelial apoptosis (Chlopicki S, Gryglewski R J. Endothelial secretory function and atherothrombosis in “The Eicosanoids”, chapter 23, 267-276. ed. P. Curtis-Prior, John Wiley and Sons, Ltd, 2004). This means that deficiency of PGI₂ may trigger or enhance inflammatory and thrombotic processes in vascular wall, which are now considered to be the key elements of atherosclerosis.

It has been accepted that elevated low-density lipoprotein cholesterol (LDL) and/or triglyceride (TG) plasma levels represent major risk factors for the development of atherosclerosis (Levine G N, Keaney J F Jr, Vita J A. Cholesterol reduction in cardiovascular disease. Clinical benefits and possible mechanisms. N Engl J Med 1995; 332:512-521). Moreover, a low plasma level of high-density lipoprotein cholesterol (HDL) is an important independent risk factor of atherosclerosis. HDL has the potential ability to prevent and correct endothelial dysfunction by increasing availability of NO and PGI₂. (Ng D S. Treating low HDL—from bench to bedside. Clin Biochem 2004; 37:649-659; Chapman M J, Assman G, Fruchart J C, Shepherd J, Sirtoti C. Raising high-density lipoprotein cholesterol with reduction of cardiovascular risk: the role of nicotinic acid—a position paper developed by the European Consensus Panel on HDL-C. Curr Med Res Opin 2004; 20:1253-1268; Calabresi L, Gomarashi M, Franceschini G. Endothelial protection by high-density lipoproteins. Arterioscler Thromb Vasc Biol 2003; 290:2292-2300).

In WO00/40559 therapeutic and cosmetic uses of certain nicotinamide derivatives, 1,3-disubstituted pyridinium salts, including 1-methylnicotinamide (MNA⁺) and 1-methyl-N′-(hydroxymethyl)nicotinamide (MNAF⁺) salts were disclosed. It was reported that said derivatives have the utility in topical treatment of skin diseases, in particular crural ulceration, acne, psoriasis, atopic dermatitis, vitiligo, as well as burns and scalds and in wound healing. Said derivatives have also the activity of promoting hair re-growth, therefore they are useful in the treatment of hair loss of different origin. Different types of topical formutations for administration of these compounds on the skin or mucosal surface are described, like shampoo, ointments, creams, gels, lotions, solutions, aerosols, etc., and for oral administration in the treatment of skin diseases. Also, cosmetic action of these compounds was described, in particular regenerating and smoothing of the skin.

Effects of 1-methylnicotinamide chloride (MNA⁺) in some skin diseases were described in a recent publication (G

bicki J, Sysa-J

drzejowska A, Adamus J, Woźniacka A, Rybak M, Zielonka J. 1-Methylnicotinamide: a potent anti-inflammatory agent of vitamin origin. Pol J Pharmacol 2003; 55:109-112). It has been proposed that MNA⁺ displays anti-inflammatory action, though the mechanism of this effect was not elucidated.

1-Methyl-3-acetylpyridinium salt (MAP⁺), was described in a publication (Takashi Sakurai, Haruo Hosoya. Charge transfer complexes of nicotinamide-adenine dinucleotide analogs and flavine mononucleotide. Biochim. Biophys. Acta 1966; 112 (3):359-468).

Now it has been found that MAP⁺ and some of the compounds described in WO00/40559, in particular MNA⁺ and MNAF⁺ possess unique pharmacological properties associated with their ability to release endogenous prostacyclin (PGI₂) from vascular endothelium, which property distinguishes them from closely structurally related nicotinamide, nicotinic acid, trigonelline and endogenous MNA⁺ metabolites, such as 1-methyl-2-pyridone-5-carboxyamide (2-PYR) and 1-methyl-4-pyridone-3-carboxyamide (4-PYR). Surprisingly, as found by the present inventors, certain compounds are endowed with the ability to correct the lipoprotein profile, in particular to lower LDL and/or TG plasma level and to raise HDL plasma level, leading to anti-atherosclerotic effects. Independently of the effect of certain quaternary pyridinium salts of the invention on lipoprotein profile, augmentation of PGI₂ synthesis by quaternary pyridinium salts found by the present inventors may show therapeutic potential in many diseases as discussed below, where endothelial dysfunction, oxidant stress, and/or PGI₂ deficiency play a pathogenetic role, including those associated with hypercholesterolemia/hypertriglyceridemia.

BRIEF DESCRIPTION OF FIGURES OF THE DRAWING

FIG. 1 Scheme of the method for detection of thrombolytic action of drugs in vivo in rats (according to Giyglewski)

FIG. 2 Thrombolytic response induced by intravenous administration of MNA⁺ in vivo (30 mg/kg)

FIG. 3 Changes in plasma levels of 6-keto-PGF_(1α) (●) and TXB₂ (∘) after intravenous administration of MNA⁺ (30 mg/kg)

FIG. 4 Lack of thrombolytic response after intravenous administration of nicotinamide or nicotinic acid (30 mg/kg).

FIG. 5 Lack of thrombolytic response after intravenous administration of 2-PYR or trigonelline (30 mg/kg).

FIG. 6 Thrombolytic response induced by intravenous administration of MAP⁺ in vivo (30 mg/kg)

FIG. 7 Changes in plasma levels of 6-keto-PGF_(1α) (●) and TXB₂ (∘) after intravenous administration of MAP⁺ in vivo (30 mg/kg)

FIG. 8 Thrombolytic response induced by intravenous administration of MNAF⁺ (30 mg/kg)

FIG. 9 Lack of effect of MNA⁺ on collagen-induced aggregation of platelets (1 mg/ml)

FIG. 10 Lack of effect of MNA⁺ on latex-induced activation of neutrophils

The present invention provides in its first aspect the use of quaternary pyridinium salts of the formula I:

wherein R is NH₂, CH₃, or N(H)CH₂OH group, and X is pharmaceutically acceptable counterion,

for the preparation of vasoprotective agent for the treatment or prevention of conditions or diseases associated with dysfunction of vascular endothelium, oxidative stress, and/or insufficient production of endothelial prostacyclin PGI₂.

Preferably, said dysfunction of vascular endothelium, oxidative stress, and/or insufficient production of endothelial prostacyclin PGI₂ is associated with hypercholesterolemia, hypertriglyceridemia or low HDL level.

Particularly advantageous activity of the compounds of the formula I is their endothelial action associated with release of PGI₂, due to which said compounds of formula I may improve perfusion in tissues, exert anti-aggregatory, thrombolytic, anti-apoptotic, anti-atherosclerotic activity, and protect gastrointestinal mucosa.

The advantage of the invention is that thrombolytic action of the compounds of the formula I is not accompanied by hypotensive activity.

In one embodiment of the invention, said condition or the disease is atherosclerosis of vascular bed of any kind, including chronic coronary disease, ischemic cerebrovascular episode or artherosclerosis of the extremities, including thromboangigitis obliterans.

In another embodiment said condition or the disease is acute cardiovascular event associated with atherosclerosis, in particular sudden cardiac death, acute coronary syndrome (including unstable coronary artery disease, myocardial infarct), the necessity of coronary angioplasty (PCI), coronary-aortal by-pass surgery (CABG), ischemic stroke, or peripheral circulation revascularization.

In yet another embodiment said condition or disease is selected from the group of risk factors for atherosclerosis, comprising the following: hypercholesterolemia, arterial hypertension, smoking, hyperhomocysteinaemia, insulin resistance, diabetes, menopause, aging, obesity, mental stress, infections, inflammatory states, including periodontal diseases, reumathoid arthritis, allograft vasculopathy or nitrate tolerance.

In yet another embodiment said condition or the disease is dyslipidemia, in particular hypercholesterolemia or hypertriglyceridemia in particular associated with low plasma level of HDL.

In yet another embodiment said condition or disease is thrombosis that is not related directly with atherosclerosis, in particular thrombosis associated with implantation of metallic vascular prostheses (stents), coronary-aortal by-pass surgery (CABG), any type of surgery with extracorporeal circulation, hemodialysis, venous thrombo-embolic disease.

In further embodiment said condition or disease is selected from the following group: chronic heart failure, pulmonary hypertension, microvascular diabetic complications, like diabetic retinopathy and nephropathy, diabetic neuropathy, nephrotic syndrome, chronic renal failure, adults respiratory distress syndrome (ARDS), cystic fibrosis, chronic obstructive pulmonary disease (COPD), preeclampsia/eclampsia, erectile dysfunction, Stein-Leventhal syndrome, sleep apnea, systemic lupus erythematosus, sickle cell anemia, non-specific inflammatory bowel diseases, gastric or duodenal ulcers, glaucoma, chronic liver disease, primary amyloidosis, neurodegenerative diseases, in particular neurodegenerative disease selected from vascular dementia, Alzheimer's disease and Parkinson's disease.

Also advantageous is the use of the compounds of formula I for the preparation of a medicament for prophylaxis or treatment of gastric or duodenal ulcer.

In a further preferred embodiment said condition or disease is chronic liver disease, in particular chronic viral hepatitis.

In a further preferred embodiment said condition or disease is chronic obstructive pulmonary disease (COPD).

Said medicament may be in a form suitable for any administration route, such as oral, parenteral, intranasal or inhalation route. Such route of administration will depend of course on the particular state or disease being treated.

In case of a medicament intended for the treatment of chronic obstructive pulmonary disease (COPD) it will preferably be presented in the form suitable for inhaled administration via the inhalation route.

As defined above, X-may be any physiologically acceptable counterion. Thus, salts of the formula I may be derived from any physiologically acceptable acid, both organic and inorganic. Suitable salts with inorganic acids are for example chloride, bromide, iodide and carbonate; suitable salts with organic acids may be salts with mono-, di- and tricarboxylic acids, for example acetate, benzoate, salicylate, hydroxyacetate, lactate, malonate and citrate. Preferred salts are chlorides, benzoates, lates, acetates, citrates and lactates; especially advantageous are chlorides.

Specific compounds of the formula (I) are 1-methylnicotinamide salts (MNA⁺), 1-methyl-3-acetylpyridinium salts (MAP⁺) and 1-methyl-N′-(hydroxymethyl)nicotinamide salts (MNAF⁺).

The invention in the second aspect provides a method of treatment and/or prevention of conditions or diseases associated with dysfunction of vascular endothelium, oxidative stress, and/or insufficient production of endothelial PGI₂ (associated or not with hypercholesterolemia, hypertriglyceridemia or low HDL level), in particular such as discussed above, comprising administration to a subject in a need of such treatment a therapeutically effective amount of a quaternary pyridinium salt of formula I as defined above

In one embodiment of the method of treatment according to the invention said condition or the disease is atherosclerosis of vascular bed of any kind, including chronic coronary disease, ischemic cerebrovascular episode or artherosclerosis of the extremities, including thromboangigitis obliterans.

In another embodiment of the method of treatment according to the invention the said condition or disease is acute cardiovascular event associated with atherosclerosis, in particular sudden cardiac death, acute coronary syndrome (including unstable coronary artery disease, myocardial infarct), the necessity of coronary angioplasty (PCI), coronaryaortal by-pass surgery (CABG), ischemic stroke, or peripheral circulation revascularization.

In yet another embodiment of the method of treatment according to the invention said condition or disease is selected from the group of risk factors for atherosclerosis, comprising the following: hypercholesterolemia, arterial hypertension, smoking, hyperhomocysteinaemia, insulin resistance, diabetes, menopause, aging, obesity, mental stress, infections, inflammatory states, including periodontal diseases, reumathoid arthritis, allograft vasculopathy or nitrate tolerance.

In yet another embodiment of the method of treatment according to the invention said condition or the disease is dyslipidemia, in particular hypercholesterolemia or hypertriglyceridemia, in particular associated with low plasma level of HDL.

In yet another embodiment of the method of treatment according to the invention said condition or disease is thrombosis that is not related directly with atherosclerosis, in particular thrombosis associated with implantation of metallic vascular prostheses (stents), coronary-aortal bypass surgery (CABG), any type of surgery with extracorporeal circulation, hemodialysis, venous thrombo-embolic disease.

In a further embodiment of the method of treatment according to the invention said condition or disease is selected from the following group: chronic heart failure, pulmonary hypertension, microvascular diabetic complications, like diabetic retinopathy and nephropathy, diabetic neuropathy, nephrotic syndrome, chronic renal failure, adults respiratory distress syndrome (ARDS), cystic fibrosis, chronic obstructive pulmonary disease (COPD), preeclampsia/eclampsia, erectile dysfunction, Stein-Leventhal syndrome, sleep apnea, systemic lupus erythematosus, sickle cell anemia, non-specific inflammatory bowel diseases, gastric or duodenal ulcers, glaucoma, chronic liver disease, primary amyloidosis, neurodegenerative diseases, in particular neurodegenerative disease selected from vascular dementia, Alzheimer's disease and Parkinson's disease.

In a further preferred embodiment said condition or disease is chronic liver disease, in particular chronic viral hepatitis.

In a further preferred embodiment said condition or disease is chronic obstructive pulmonary disease (COPD).

Also advantageous is the use of the compounds of formula I in the method of prophylaxis or treatment of gastric or duodenal ulcer.

Quaternary pyridinium salts of formula I may be administered alone or in combination with other cardiovascular agent.

Pyridinium salts of formula I may be administered in particular orally, in the form of conventional oral preparations, such as tablets, capsules, oral solutions/suspensions in pharmaceutically acceptable liquid carrier. Said formulations may be prepared using conventional methods known in the art and include conventional pharmaceutical excipients and carriers.

Pyridinium salts of formula I may be also administered parenterally, in the form of injections, including subcutaneous and intravenous injections and infusions.

Other contemplated routes of administration are by inhalation, intranasally and rectally.

In any case the route of administration will of course depend on the particular disease being treated.

For example, in case of a treatment of chronic obstructive pulmonary disease (COPD) pyridinium salts it will preferably be administered in the form suitable for inhaled administration via the inhalation route.

Daily dose of the pyridinium salts of the formula I may be in the range of 10 to 1000 mg and may be administered in single or divided doses.

The present invention relates also to a method for enhancing a prostacyclin levels in mammals, which comprises oral administration of effective amount of quaternary pyridinium salt of formula I as defined above.

The present invention provides also quaternary pyridinium salts of formula I as defined above, for use in oral diet supplementation. Pyridinium salts of formula I, when used as an oral diet supplement, enhance the prostacyclin level, thereby acting as vasoprotective agents.

The present invention provides further a use of pyridinium salts of the formula I as defined above, for the preparation of nutritional preparation for vascular protection in mammals in states or diseases associated with dysfunction of vascular endothelium, oxidative stress, and/or insufficient production of endothelial prostacyclin (PGI₂), in particular associated with hypercholesterolemia, hypertriglyceridemia or low HDL level.

Said condition or disease wherein nutritional preparation may be administered is atherosclerosis, especially in patients with chronic coronary disease, ischemic cerebrovascular episode or artherosclerosis of the extremities, including thromboangigitis obliterans.

Said condition or disease wherein nutritional preparation may be administered may be also selected from the group of risk factors for atherosclerosis, comprising the following: hypercholesterolemia, arterial hypertension, smoking, hyperhornocysteinaemia, insulin resistance, diabetes, menopause, aging, obesity, mental stress, infections, inflammatory states, including periodontal diseases, reumathoid arthritis, allograft vasculopathy or nitrate tolerance.

Said condition or disease wherein nutritional preparation may be administered is dyslipidemia, in particular hypercholesterolemia, hypertriglyceridemia in particular associated with low plasma level of HDL.

Said condition or disease wherein nutritional preparation may be administered may be also thrombosis that is not related directly with atherosclerosis, in particular thrombosis associated with implantation of metallic vascular prostheses (stents), coronary-aortal by-pass surgery (CABG), any type of surgery with extracorporeal circulation, hemodialysis, venous thrombo-embolic disease.

Specific pyridinium salts for use in diet supplementation and/or as nutritional preparation are compounds of the formula (I), wherein R is CH₃ group.

Specific pyridinium salts for use in diet supplementation and/or as nutritional preparation are compounds of the formula (I), wherein R is NH₂ group.

Specific pyridinium salts for use in diet supplementation and/or as nutritional preparation are compounds of the formula (I), wherein R is N(H)CH₂OH group.

Dietary supplements and nutritional preparations may have the form suitable for oral ingestion, such as tablets, capsules, solutions and suspensions for drinking, and similar, conventional and known in pharmaceutical art and prepared according to techniques known in the art with the use of conventional excipients and carriers.

Advantageously, dietary supplement or nutritional preparation may incorporate at least 5% by weight of the pyridinium salt of the formula I.

The invention is further illustrated by the following Examples, which show pharmacological activity of pyridinium salts.

EXAMPLE I

Thrombolytic Activity

Thrombolytic activity of quaternary pyridinium salts was assessed using original method of Gryglewski et al., (Gryglewski R J, Korbut R, Ocetkiewicz A, Stachura J. In vivo method for quantitation for anti-platelet potency of drugs. Naunyn Schmiedebergs Arch Pharmacol 1978; 302:25-30), the scheme of which was shown on FIG. 1.

Wistar rats of body weight 300-350 g were anaesthetised (thiopental 30 mg kg⁻¹ i.p.) and heparinised (unfractionated heparin 800 i.u. kg⁻¹ i.v.). Arterial blood pressure was measured from cannulated right carotid artery, and extracorporal circulation was established between left carotid artery and left jugular vein. A collagen strip from rabbit tendon of Achilles was superfused with arterial blood in extracorporal circulation at a rate of 1.5 ml min⁻¹ and its weight was continuously monitored by an auxotonic Harvard transducer.

During the initial 20-30 min of superfusion the strip was gaining in weight by 80-120 mg because of deposition of platelet-rich thrombi and then in control conditions stayed unchanged during next 3-5 hrs. Thrombolytic response was detected by a fall in weigth of a thrombi. Araerial blood pressure was also monitored, so this model enabled the analysis of thrombolytic and hypotensive action of a compound (FIG. 1).

The analysis of the thrombolytic response in this experimental set-up was complemented by the assay of 6-keto-PGF_(1α), TXB₂ and PGE₂ in arterial blood plasma. For this purpose blood samples (500 μl) were collected in Eppendorff tubes with indomethacin to yield its final concentration of 10 μM, and EDTA to yield the final concentration of 1 mM. Then, the blood samples were spinned for 5 min at 2.000×g. Plasma samples were stored at −70° C. The prostanoids were assayed using the enzyme immunoassay kits (Cayman Chemical Co, Ann Arbor, Mich.).

Intravenous administration of MNA⁺ (3-30 mg/kg) produced a concentration-dependent thrombolysis in Wistar rats with extracorporal circulation. A maximum response was observed at the MNA⁺ dose of 30 mg/kg. Single injection of MNA⁺ at a dose of 30 mg/kg induced a long-lasting thrombolytic response at the level of 42±4% and remained at approximately the same level for 2-3 hours of the observation period. In contrast to MNA⁺, nicotinamide, nicotinic acid, trigonelline and 2-PYR (endogenous metabolite of MNA⁺), each of them at 30 mg/kg, failed to induce a significant thrombolytic response. Nicotinamide and nicotinic acid-induced responses were transient (less then 15-20 minutes) and at their maximum amounted merely to 9±0.6%, 5±0.9%, respectively). Trigonelline did not produce any thrombolytic response and response to 2-PYR was also very weak (<10%) and transient (<15 min). The potency and duration of thrombolytic responses to MNA⁺, nicotinamide and nicotinic acid correlated with a pattern of 6-keto-PGF_(1α) release to arterial plasma induced by these compounds. MNA⁺ (30 mg/kg) induced a substantial increase in levels of 6-keto-PGF_(1α) as early as 15 minutes after drug injection (from 104±7 to 460±58 pg/ml) which than reached its plateau of around 400 pg/ml for at least one hour. On the other hand neither TXB₂ nor PGE₂ levels changed significantly in response to MIKA⁺. Sluggish rise in TXB₂ levels was time-dependent and observed also after saline injection. Levels of 6-keto-PGF_(1α) did not increase after injection of nicotinamide or after injection of nicotinic acid (30 mg/kg).

In the presence of indomethacin (5 mg/kg) thrombolytic response to MNA⁺ was abrogated, similarly as MNA-induced release of 6-keto-PGF_(1α). Importantly, thrombolysis induced by MNA⁺ (30 mg/kg) was not associated with a fall in arterial blood pressure. Collagen-induced aggregation in platelet-rich plasma in vitro was not affected by MNA⁺ up to concentration of 10 mM, this excluding the possibility that dissipation of platelet-rich thrombi in vivo was due to the direct effect of MNA⁺ on platelets. Furthermore MNA⁺ (1 mM) did not inhibit latex-induced activation of neutrophils, this suggesting a possible selectivity of MNA⁺ towards endothelium.

FIG. 2 shows thrombolytic response in vivo induced by MNA⁺, and FIG. 3 shows a concomitant increase in level of 6-keto-PGF_(1α) (stable PGI₂ metabolite) in blood. Nicotinamide, nicotinic acid (FIG. 4), trigonelline and 2-PYR (FIG. 5) did not display a significant thrombolytic activity. However, MAP⁺ (30 mg/kg) and MNAF⁺ (30 mg/kg) each of them induced a thrombolytic response (FIG. 6 and FIG. 8) that was comparable to that induced by 30 mg/kg of MNA⁺. MAP⁺-induced thrombolysis was associated with the release of PGI₂ (FIG. 7), similarly as in the case of MNA⁺-induced thrombolysis. MNA⁺ (30-300 mg/kg) did not cause hypotension. As shown on FIG. 9 and FIG. 10, MNA⁺ did not inhibit collagen-induced aggregation of platelets and latex-induced activation of neutrophils. The former response depends on COX1-TXA₂ and was abrogated by aspirin, whereas the latter one depends on NADPH oxidase and was abrogated by DPI or apocynin.

EXAMPLE 2

An Ant-Athrogenic Effect In vivo in patients

The anti-atherogenic effect of MNA⁺ was investigated in 15 dyslipidemic patients.

The enrollment criteria were: high level of TG (≧250 mg/dl) and low level of HDL (≦35 mg/dl for male, ≦45 mg/dl for female). The mean age of the patients was 61.4 (range 45-81 years).

The patients were treated with MNA⁺ for 2 weeks. The MNA⁺ was administered orally, three times a day, one capsule (30 mg MNA⁺) after meal.

The plasma levels of TC, TG, HDL were measured at baseline and after 2 weeks of therapy. The level of LDL was measured in those cases, where it was possible (due to high TG level).

It has been found that MNA⁺ reduced the TC (267.0 vs. 225.1 mg/dl) (−15.7%) and TG (472.6 vs 249.9 mg/dl) (−47.1%) levels between the baseline and 2 weeks measurements. The increase of the HDL (39.2 vs. 53.4 mg/dl) (36.2%) level was also observed after 2 weeks therapy. The significant reduction of TG/HDL ratio (13.9 vs. 5.8) was observed. 

The invention claimed is:
 1. A method for treatment of atherosclerosis in a subject in need thereof, said method comprising administering to said subject a quaternary pyridinium salt of formula I:

in an amount effective to increase the release of endogenous prostacyclin (PGI₂) from the vascular endothelium of said subject and thereby treating said atherosclerosis in said subject, wherein R is NH₂, CH₃ or N(H)CH₂OH, and X is a pharmaceutically acceptable counterion.
 2. The method of claim 1, wherein said atherosclerosis is atherosclerotic coronary artery disease, ischemic cerebrovascular episode, atherosclerosis of the extremities, or thromboangigitis obliterans.
 3. The method of claim 1, wherein said subject is additionally in need of a treatment of one or more acute cardiovascular events selected from the group consisting of: sudden cardiac death, acute coronary syndrome, coronary angioplasty (PCI), coronary-aortal by-pass surgery (CABG), ischemic stroke, and peripheral circulation revascularization.
 4. The method of claim 1, wherein said subject has one or more risk factors for atherosclerosis selected from the group consisting of: arterial hypertension, smoking, hyperhomocysteinaemia, insulin resistance, diabetes, obesity, mental stress, infections, inflammation, rheumatoid arthritis, allograft vasculopathy and nitrate tolerance.
 5. The method of claim 1, wherein said subject is in menopause or is 45-81 years old.
 6. The method of claim 1, wherein said quaternary pyridinium salt is administered orally.
 7. The method of claim 1, wherein said quaternary pyridinium salt is administered parenterally.
 8. The method of claim 1, wherein said pyridinium salt is administered in the form of a composition with a pharmaceutically acceptable carrier.
 9. The method of claim 1, wherein said quaternary pyridinium salt is a 1-methylnicotinamide salt.
 10. The method of claim 1, wherein said quaternary pyridinium salt is a 1-methyl-3-acetylpyridinium salt.
 11. The method of claim 1, wherein said quaternary pyridinium salt is a 1-methyl-N′-(hydroxymethyl) nicotinamide salt.
 12. The method of claim 1, said method further comprising administering a cardiovascular agent other than said quaternary pyridinium salt. 